1. Field of the Invention and General Technological Background
The invention concerns a process for kiln-drying malt in a floor arrangement in which there are at least two zones for preliminary drying and a zone for secondary drying and/or cooling the malt, and the unsaturated exhaust air from the secondary drying and/or cooling zone is mixed with the incoming air system as return air. The invention also relates to an apparatus for the implementation of this process with a floor arrangement, a charging and discharging device for the malt and a preliminary drying air supply and a secondary drying air supply.
In the process of drying, the so-called kiln-drying of malt, which is used for brewing, it is of great importance not only to achieve a deliberate drying of the green malt, but in addition to influence, by means of a defined temperature control of the drying air, certain malt properties which codetermine the quality and the taste of the end product in the later brewing process. Apart from these technological requirements, economic parameters must also be considered, so that the kiln-drying process proceeds as practically as possible both from the point of view of energy consumption as well as operating costs. In addition, the integration of energy-saving components in optimal fashion is especially desirable.
Today the foregoing considerations are accommodated, in accordance with the individual judgement of the economic and technological background conditions made by the individual malt enterprises, through the use of different kiln-drying systems. The most widely used are single floor and double floor kiln-drying systems, which have been used for decades past, have been constantly improved, and thereby have reached a high development state. Apart from these purely static installations from the point of view of the goods being dried, in the years of high energy prices dynamic systems were also developed using continuous malt conveyance. These three types of kiln-drying require no further explanation, because they are described in detail in the specialist literature, for example "Die Technology der Malzbereitung" by the authors Schuster/Winfurther/Narziss as well as in patents, for example DE NO. 32 24 471.1-09.
The characteristics of these kiln-drying installations can be summarized as follows: